Effects Of Legume Intercrops And Mineral Nitrogen On Nutrient Uptake And Yield Of Maize (Zea Mays L.) In Malawi

ABSTRACT

Nitrogen (N) is the critical plant nutrient. Low maize (Zea mays L.) yields in smallholder farms of Malawi are attributable to declining N fertility, aggravated by the ever increasing price of fertilizer. Maize, the country’s staple, has a high nitrogen demand. Little effort has been made to establish the best nitrogen rate in a maize- cowpea and maize-bean intercrop under variable soil conditions as a way of improving production, and was the objective of the current study. Field experiments were conducted at Chitedze Agricultural Research Station in Lilongwe and Makoka Agricultural Research Station in Zomba during the 2016/17 growing season. A split plot layout in a randomized complete block design, with three replicates was used. The main plots were; sole maize, sole bean, sole cowpea, bean/maize and cowpea/maize intercrop systems. The sub plots were N fertilizer rates (0, 52.5, 78.75 and 105 kg N ha-1 ), applied as urea. Measured parameters included plant height, leaf area index, and N uptake by the maize plant, dry matter and grain yield, legume biomass and yield, land equivalent ratio, weight and number of nodules and nutrient use efficiency. The data was subjected to analysis of variance using SAS software version 9.3 (SAS Institute Inc.) at P